Motor vehicle wheel assembly

Abstract

A motor vehicle drive wheel assembly comprising a fixed subassembly comprising two outer raceways; a rotating subassembly comprising a wheel hub, two inner raceways and two rows of rolling bodies that are arranged in two pitch planes PP 1 and PP 2 . One of the inner raceways is formed on a rolling bearing ring that bears against a transmission bowl at an annular contact interface situated between the two pitch planes.

The invention claimed is: 
     
       1. A motor vehicle drive wheel assembly, comprising:
 a fixed subassembly comprising a first annular outer raceway and a second annular outer raceway centered on a common axis of rotation; 
 a rotating subassembly, capable of rotating relative to the fixed subassembly about the axis of rotation, comprising a wheel hub comprising a flange provided with an interface for attaching a wheel rim or a brake disc, the flange having a mounting face for the wheel rim or for the brake disc axially facing in a direction of disassembly of the wheel rim or of the brake disc, the direction of disassembly being parallel to the axis of rotation, the mounting face being coplanar with an assembly reference plane, the assembly reference plane perpendicular to the axis of rotation, a transmission bowl, and at least one inner rolling bearing ring, the inner rolling bearing ring being shrunk over a shrink-fit seat of the wheel hub, the inner rolling bearing ring bearing against the transmission bowl at an annular contact interface extending at least in a radial direction with respect to the axis of rotation, the rotating subassembly further comprising a first inner raceway located opposite the first outer raceway and a second inner raceway located opposite the second outer raceway and formed on the inner rolling bearing ring; and 
 rolling bodies, forming a first row of rolling bodies capable of rolling on the first outer raceway and the first inner raceway and a second row of rolling bodies capable of rolling on the second outer raceway and the second inner raceway, a first pitch plane containing the centers of the rolling bodies of the first row of rolling bodies being located at a non-zero distance from a second pitch plane containing the centers of the rolling bodies of the second row of rolling bodies, in the direction of disassembly, the first row of rolling bodies and the second row of rolling bodies being located on the same outer side of a limit plane of the drive wheel assembly tangential to the rolling bodies of the second row of rolling bodies and perpendicular to the axis of rotation; wherein 
 the annular contact interface between the inner rolling bearing ring and the annular bearing face of the transmission bowl is positioned at least partially between the first pitch plane and the limit plane and has a maximum contact diameter that is greater than a diameter of the shrink-fit seat and less than a raceway bottom diameter of the second inner raceway. 
 
     
     
       2. The motor vehicle drive wheel assembly of  claim 1 , wherein the annular contact interface is positioned at least partially between the first pitch plane and the second pitch plane. 
     
     
       3. The motor vehicle drive wheel assembly of  claim 2 , wherein the annular contact interface between the inner rolling bearing ring and the annular bearing face of the transmission bowl is positioned completely between the first pitch plane and the limit plane and has a maximum contact diameter that is greater than the diameter of the shrink-fit seat and less than a raceway bottom diameter of the second inner raceway. 
     
     
       4. The motor vehicle drive wheel assembly of  claim 1 , wherein the first outer raceway has a raceway bottom diameter smaller than a raceway bottom diameter of the second inner raceway. 
     
     
       5. The motor vehicle drive wheel assembly of  claim 1 , wherein the transmission bowl has a cavity comprising rolling tracks, the rolling tracks having a track bottom diameter satisfying at least one of the following conditions:
 the track bottom diameter is greater than a raceway bottom diameter of the first inner raceway, 
 the track bottom diameter is less than a raceway bottom diameter of the second inner raceway; or 
 the track bottom diameter is greater than the maximum contact diameter of the annular contact interface. 
 
     
     
       6. The motor vehicle drive wheel assembly of  claim 1 , wherein the rolling bodies are balls, the balls forming the first row of rolling bodies having a first ball diameter less than or equal to a second ball diameter of the balls forming the second row of rolling bodies. 
     
     
       7. The motor vehicle drive wheel assembly of  claim 6 , wherein the inner rolling bearing ring has an end face facing axially in the direction of disassembly, and located at a spacing distance from a plane containing the points of the annular contact interface furthest from the axis of rotation, the spacing distance being less than one and a half times the first ball diameter. 
     
     
       8. The motor vehicle drive wheel assembly of  claim 6 , wherein the maximum contact diameter of the annular contact interface is less than the sum of twice the first ball diameter and the diameter of the shrink-fit seat. 
     
     
       9. The motor vehicle drive wheel assembly of  claim 1 , further comprising a transmission nut and rolling transmission bodies, the rolling transmission bodies having centers and being guided by rolling tracks formed in a cavity of the transmission bowl and on the transmission nut, the transmission nut, the rolling transmission bodies and the transmission bowl forming a transmission joint defining a pitch plane of the transmission joint and a pitch diameter of the transmission joint, the pitch plane of the transmission joint being perpendicular to the common axis of rotation and containing the centers of the rolling transmission bodies, the pitch diameter of the transmission joint being twice the distance as a distance between the centers of the rolling transmission bodies and the common axis of rotation. 
     
     
       10. The motor vehicle drive wheel assembly of  claim 9 , wherein the maximum contact diameter of the annular contact interface is less than the pitch diameter of the transmission joint. 
     
     
       11. The motor vehicle drive wheel assembly of  claim 9 , wherein the pitch plane of the transmission joint is located at an inter-planar distance from the assembly reference plane and satisfies at least one of the following conditions:
 the inter-planar distance is less than a pitch diameter of the second row of rolling bodies; and/or 
 the inter-planar distance CA is less than thirteen sevenths of an axial distance measured between the assembly reference plane and the second pitch plane; and/or 
 a ratio between the inter-planar distance and a distance between the first pitch plane and the second pitch plane is less than 4.75; and/or 
 a ratio between the difference between the inter-planar distance and an axial distance between the assembly reference plane and the second pitch plane and a pitch diameter of the second row of rolling bodies, is less than 0.45. 
 
     
     
       12. The motor vehicle drive wheel assembly of  claim 1 , wherein the annular contact interface is planar. 
     
     
       13. The motor vehicle drive wheel assembly of  claim 1 , wherein the annular contact interface is flared and has a first vertex angle satisfying at least one of the following conditions:
 the first vertex angle is between 100° and 140°; or 
 the first vertex angle is equal, to within +/−10°, to a second vertex angle of a frustoconical inner face of the transmission bowl, opposite the annular contact interface. 
 
     
     
       14. The motor vehicle drive wheel assembly of  claim 1 , wherein a ratio between the maximum contact diameter of the annular contact interface and a pitch diameter of the second row of rolling bodies less than 0.65. 
     
     
       15. The motor vehicle drive wheel assembly of  claim 1 , wherein the transmission bowl comprises a splined end portion mounted in a splined tubular portion of the wheel hub, forming a splined contact interface. 
     
     
       16. The motor vehicle drive wheel assembly of  claim 15 , wherein the splined contact interface has a spline pitch diameter and the annular contact interface is located axially at an axial distance from the assembly reference plane, such that the sum of the spline pitch diameter and the axial distance is less than a pitch diameter of the second row of rolling bodies. 
     
     
       17. The motor vehicle drive wheel assembly of  claim 15 , wherein a distance between an end of the splined contact interface axially closest to the annular contact interface and the assembly reference plane is less than four-fifths of a length between the assembly reference plane and the second pitch plane. 
     
     
       18. The motor vehicle drive wheel assembly of  claim 1 , wherein the wheel hub is a solid one-piece metal part. 
     
     
       19. The motor vehicle drive wheel assembly of  claim 1 , wherein the rotating subassembly further comprises a brake disc bearing on the mounting face, a wheel rim bearing on the brake disc and elements for attaching the wheel rim and the brake disc to the flange. 
     
     
       20. The motor vehicle drive wheel assembly of  claim 1 , wherein the annular contact interface between the inner rolling bearing ring and the annular bearing face of the transmission bowl is positioned completely between the first pitch plane and the limit plane and has a maximum contact diameter that is greater than the diameter of the shrink-fit seat and less than a raceway bottom diameter of the second inner raceway.